Question

A person invested &18,000 in two schemes - Scheme X at 15% p.a. and Scheme Y at 10% p.a., both under simple interest. After 1 year, the total interest from both schemes was ₹2,160. How much was invested in Scheme X?

• A. ₹6000
• B. ₹7000
• C. ₹7200
• D. ₹6200

Answer 1

Answer:

C. ₹7200

Let the amount invested in Scheme X be (x).
Then Scheme Y gets (18000 - x).

Both are for 1 year under simple interest.

Step 1: Write interest expressions

Scheme X:
$15\% \text{ of } x = 0.15x$

Scheme Y:
$10\% \text{ of } (18000 - x) = 0.10(18000 - x)$

Total interest given

$0.15x + 0.10(18000 - x) = 2160$

Solve

$0.15x + 1800 - 0.10x = 2160$
$0.05x + 1800 = 2160$
$0.05x = 360$
$x = \frac{360}{0.05} = 7200$